(a) Technical Field
The present invention relates to a high-hardness clear coating material, and in particular, to a high-hardness clear coating material capable of improving the hardness and gloss of aluminum.
(b) Description of the Related Art
Technology for forming an anodizing layer (2) and a corrosion resistant coating layer (3) is currently used in order to improve the hardness and gloss of an aluminum material (1), FIG. 1. This is a technology for forming an anodizing layer (2) having high hardness through an anodizing treatment, and forming a clear corrosion resistant coating layer (3) in order to improve gloss and corrosion resistance.
Materials forming the corrosion resistant coating layer (3) include, in % by weight, 30% to 40% of a polyester resin, 20% to 30% of an isocyanate curing agent, 15% to 20% of an aromatic solvent, 15% to 20% of a cyclohexanone solvent, and 4% to 8% of a pulverized silica matting agent.
The shape of a clear coating layer according to the technology described above is shown in FIG. 1.
However, such a clear coating layer has a problem in that a corrosion resistant coating layer (3) tends to become damaged when anodizing layer (2) is brittle fractured during molding. When the anodizing layer (2) and the corrosion resistant coating layer (3) are damaged as described above, problems such as external cracks and peeling tend to occur, and corrosion develops around the damaged area.
When the anodizing layer (2) is not included, damage to the corrosion resistant coating layer (3) due to the brittle fracture of the anodizing layer (2) may be prevented; however, the corrosion resistant coating layer (3) itself cannot satisfy required hardness, and surface scratches readily occur. In addition, even when a corrosion resistant coating layer (3) having strong hardness is prepared, moldability is disadvantageously reduced, which causes end fractures and cracks to occur. These problems arise since the hardness of polyester resin, a main material of the corrosion resistant coating layer (3), is low.
Accordingly, a coating material having improved hardness and corrosion resistance thereby capable of solving such problems has been required.
The description provided above as a related art of the present invention is just for helping in understanding the background of the present invention and should not be construed as being included in the related art known by those skilled in the art.